Combinatorial Testing for Tree-Structured Test Models with Constraints

In this paper, we develop a combinatorial testing technique for tree-structured test models. First, we generalize our previous test models for combinatorial testing based on and-xor trees with constraints limited to a syntactic subset of propositional logic, to allow for constraints in full propositional logic. We prove that the generalized test models are strictly more expressive than the limited ones. Then we develop an algorithm for combinatorial testing for the generalized models, and show its correctness and computational complexity. We apply a tool based on our algorithm to an actual ticket gate system that is used by several large transportation companies in Japan. Experimental results show that our technique outperforms existing techniques.